U.S. patent application number 11/400989 was filed with the patent office on 2007-10-11 for cutting members for shaving razors.
Invention is credited to Michael J. Bond, Joseph A. DePuydt, Matthew J. Guay, William Masek, Ming Laura Xu.
Application Number | 20070234576 11/400989 |
Document ID | / |
Family ID | 38430425 |
Filed Date | 2007-10-11 |
United States Patent
Application |
20070234576 |
Kind Code |
A1 |
Masek; William ; et
al. |
October 11, 2007 |
Cutting members for shaving razors
Abstract
A cutting member for a shaving razor includes an elongated blade
portion that tapers to a cutting edge, an elongated base portion
that is integral with the blade portion, and a bent portion,
intermediate the blade portion and the base portion. In some
implementations, at least part of the cutting member has a
thickness of at least about 0.005 inch (0.127 millimeter).
Inventors: |
Masek; William; (North
Attleboro, MA) ; Guay; Matthew J.; (North Attleboro,
MA) ; Bond; Michael J.; (Duxbury, MA) ;
DePuydt; Joseph A.; (Quincy, MA) ; Xu; Ming
Laura; (Wayland, MA) |
Correspondence
Address: |
FISH & RICHARDSON P.C.
P.O. BOX 1022
MINNEAPOLIS
MN
55440-1022
US
|
Family ID: |
38430425 |
Appl. No.: |
11/400989 |
Filed: |
April 10, 2006 |
Current U.S.
Class: |
30/346.54 |
Current CPC
Class: |
C22C 38/02 20130101;
C21D 1/18 20130101; B21D 53/645 20130101; B26B 21/58 20130101; C22C
38/22 20130101; C21D 6/002 20130101; B26B 21/4031 20130101; B26B
21/4068 20130101; C22C 38/04 20130101; C21D 1/02 20130101; C21D
9/18 20130101; C21D 9/0068 20130101; B26B 21/565 20130101 |
Class at
Publication: |
30/346.54 |
International
Class: |
B26B 21/54 20060101
B26B021/54 |
Claims
1. A cutting member for a shaving razor, the cutting member
comprising an elongated blade portion that tapers to a cutting
edge; an elongated base portion that is integral with the blade
portion; and a bent portion, intermediate the blade portion and the
base portion, wherein at least part of the cutting member has a
thickness of at least about 0.005 inch (0.127 millimeter).
2. The cutting member of claim 1, wherein the cutting member has an
average thickness of about 0.005 inch (0.127 millimeter) to about
0.01 inch (0.254 millimeter).
3. The cutting member of claim 2, wherein substantially the entire
elongated blade, except for the cutting edge, has a thickness of
0.005 inch (0.127 millimeter) to about 0.01 inch (0.254
millimeter).
4. The cutting member of claim 1, wherein the bent portion has an
average thickness that is at least about 5 percent less than an
average thickness of the base portion.
5. The cutting member of claim 1, wherein the base portion has a
hardness of about 540 HV to about 750 HV.
6. The cutting member of claim 1, wherein the elongated base
portion is configured to be secured to the shaving razor.
7. The cutting member of claim 1, wherein the elongated blade
portion and the elongated base portion are substantially
planar.
8. The cutting member of claim 7, wherein the elongated blade
portion extends at an angle of about 108 degrees to about 115
degrees relative to the elongated base portion.
9. The cutting member of claim 1, wherein the elongated blade
portion has a bow of about +0.010 to -0.050 millimeters or less
across the length of the blade portion.
10. The cutting member of claim 1, wherein the elongated blade
portion has a sweep of about .+-.0.070 millimeters or less across
the length of the blade portion.
11. The cutting member of claim 1, wherein the bent portion has a
bend radius of about 0.020 inch (0.45 millimeter) or less.
12. The cutting member of claim 1, wherein the cutting member is
formed of a metal comprising about 0.35 to about 0.43 percent
carbon, about 0.90 to about 1.35 percent molybdenum, about 0.40 to
about 0.90 percent manganese, about 13 to about 14 percent
chromium, no more than about 0.030 percent phosphorus, about 0.20
to about 0.55 percent silicon, and no more than about 0.025 percent
sulfur.
13. The cutting member of claim 1, wherein the bent portion has a
ductility of about seven percent to about 12 percent
elongation.
14. A cutting member for a shaving razor, the cutting member
comprising an elongated blade portion that tapers to a cutting
edge; an elongated base portion that is integral with the blade
portion; and a bent portion, intermediate the blade portion and the
base portion; wherein the cutting member is formed of a material
about 0.35 to about 0.43 percent carbon, about 0.90 to about 1.35
percent molybdenum, about 0.40 to about 0.90 percent manganese,
about 13 to about 14 percent chromium, no more than about 0.030
percent phosphorus, about 0.20 to about 0.55 percent silicon, and
no more than about 0.025 percent sulfur.
15. A cutting member for a shaving razor, the cutting member
comprising an elongated blade portion that tapers to a cutting
edge; an elongated base portion that is integral with the blade
portion; and a bent portion intermediate the blade portion and the
base portion; wherein at least part of the cutting member has a
ductility of at least about seven percent elongation.
16. The cutting member of claim 15, wherein the bent portion has a
ductility of about seven percent to about 12 percent
elongation.
17. The cutting member of claim 16, wherein the bent portion has a
ductility of about nine percent to about ten percent
elongation.
18. The cutting member of claim 15, wherein the cutting member has
an average thickness of about 0.005 inch (0.127 millimeter) to
about 0.01 inch (0.254 millimeter).
19. A cutting member for a shaving razor, the cutting member
comprising: a first portion; a second portion; and a bent portion
intermediate the first and second portions, the bent portion having
a thickness that is at least about five percent less than an
average thickness of the cutting member.
20. The cutting member of claim 19, wherein the thickness of the
bent portion is about five percent to about 30 percent less than
the average thickness of the cutting member.
21. The cutting member of claim 20, wherein the average thickness
of the cutting member is about 0.005 inch (0.127 millimeter) to
about 0.01 inch (0.254 millimeter).
22. The cutting member of claim 21, wherein the thickness of the
bent portion is about 0.0035 inch (0.089 millimeter) to about
0.0095 inch (0.241 millimeters).
23. The cutting member of claim 19, wherein the bent portion has a
ductility of about seven percent to about 12 percent
elongation.
24. A method comprising: deforming a continuous strip of material;
and then separating the continuous strip into multiple discrete
blades, each blade having a first portion, a second portion, and a
bent portion intermediate the first and second portions.
25. The method of claim 24, wherein deforming the continuous strip
of material comprises pressing the strip of material between a
punch and a die.
26. The method of claim 24, wherein separating the continuous strip
comprises stamping the strip.
27. The method of claim 24, wherein separating the continuous strip
comprises punching the strip.
28. The method of claim 24, further comprising punching
longitudinally spaced apart slots in the strip prior to deforming
the strip, the slots at least partially separating regions of the
strip corresponding to the blades.
29. The method of claim 24, wherein the continuous strip of
material comprises a metal strip.
30. The method of claim 29, wherein the metal strip comprises about
0.35 to about 0.43 percent carbon, about 0.90 to about 1.35 percent
molybdenum, about 0.40 to about 0.90 percent manganese, about 13 to
about 14 percent chromium, no more than about 0.030 percent
phosphorus, about 0.20 to about 0.55 percent silicon, and no more
than about 0.025 percent sulfur.
31. The method of claim 24, wherein the continuous strip has an
average thickness of about 0.005 inch (0.127 millimeter) to about
0.01 inch (0.254 millimeter).
32. A method comprising: hardening a strip of blade steel; forming
a cutting edge on the hardened strip; after forming the cutting
edge, bending the strip along its length by coining the strip; and
separating the bent strip into individual blades, each blade having
a bent portion.
33. The method of claim 32, wherein bending the strip comprises
using a forming die that is configured so as not to touch the
cutting edge.
34. The method of claim 32, wherein bending the strip reduces the
thickness of the blade steel in the bent portion by at least about
five percent relative to an original thickness of the blade
steel.
35. The method of claim 34, wherein the blade steel comprises about
0.35 to about 0.43 percent carbon, about 0.90 to about 1.35 percent
molybdenum, about 0.40 to about 0.90 percent manganese, about 13 to
about 14 percent chromium, no more than about 0.030 percent
phosphorus, about 0.20 to about 0.55 percent silicon, and no more
than about 0.025 percent sulfur.
Description
TECHNICAL FIELD
[0001] This invention relates to cutting members for shaving
razors.
BACKGROUND
[0002] Razor blades are typically formed of a suitable metallic
sheet material such as stainless steel, which is slit to a desired
width and heat-treated to harden the metal. The hardening operation
utilizes a high temperature furnace, where the metal may be exposed
to temperatures greater than 1145.degree. C. for up to 18 seconds,
followed by quenching.
[0003] After hardening, a cutting edge is formed on the blade. The
cutting edge typically has a wedge-shaped configuration with an
ultimate tip having a radius less than about 1000 angstroms, e.g.,
about 200-300 angstroms.
[0004] The razor blades are generally mounted on bent metal
supports and attached to a shaving razor (e.g., a cartridge for a
shaving razor). FIG. 1, for example, illustrates a prior art razor
blade assembly that includes a planar blade 10 attached (e.g.,
welded) to a bent metal support 11. Blade 10 includes a tapered
region 14 that terminates in a cutting edge 15 16. This type of
assembly is secured to shaving razors (e.g., to cartridges for
shaving razors) to enable users to cut hair (e.g., facial hair)
with cutting edge 16. Bent metal support 11 provides the relatively
delicate blade 10 with sufficient support to withstand forces
applied to blade 10 during the shaving process. Examples of razor
cartridges having supported blades are shown in U.S. Pat. No.
4,378,634 and in U.S. patent application Ser. No. 10/798,525, filed
Mar. 11, 2004, which are incorporated by reference herein.
SUMMARY
[0005] In some aspects, the invention features a cutting member for
a shaving razor, the cutting member including an elongated blade
portion that tapers to a cutting edge; an elongated base portion
that is integral with the blade portion; and a bent portion,
intermediate the blade portion and the base portion.
[0006] In one such aspect, at least part of the cutting member has
a thickness of at least about 0.005 inch (0.127 millimeter).
[0007] In another such aspect, the cutting member is formed of a
material about 0.35 to about 0.43 percent carbon, about 0.90 to
about 1.35 percent molybdenum, about 0.40 to about 0.90 percent
manganese, about 13 to about 14 percent chromium, no more than
about 0.030 percent phosphorus, about 0.20 to about 0.55 percent
silicon, and no more than about 0.025 percent sulfur.
[0008] In yet another of these aspects, at least part of the
cutting member has a ductility of at least about seven percent
elongation.
[0009] Some embodiments include one or more of the following
features. The cutting member may have an average thickness of about
0.005 inch (0.127 millimeter) to about 0.01 inch (0.254
millimeter); in some cases substantially the entire elongated
blade, except for the cutting edge, has a thickness in this range.
The bent portion may have an average thickness that is at least
about 5 percent less than an average thickness of the base portion.
The elongated base portion may be configured to be secured to the
shaving razor. The elongated blade portion may extend at an angle
of about 108 degrees to about 115 degrees relative to the elongated
base portion.
[0010] The invention also features a cutting member for a shaving
razor, the cutting member including a first portion; a second
portion; and a bent portion intermediate the first and second
portions, the bent portion having a thickness that is at least
about five percent less than an average thickness of the cutting
member.
[0011] The invention also features methods of making cutting
members and razors including such members.
[0012] In one aspect, the invention features a method including
deforming a continuous strip of material, and then separating the
continuous strip into multiple discrete blades, each blade having a
first portion, a second portion, and a bent portion intermediate
the first and second portions.
[0013] Some embodiments may include one or more of the following
features. Deforming the continuous strip of material may include
pressing the strip of material between a punch and a die.
Separating the continuous strip may include stamping or punching
the strip. The method may also include punching longitudinally
spaced apart slots in the strip prior to deforming the strip, the
slots at least partially separating regions of the strip
corresponding to the blades.
[0014] In another aspect, the invention features a method including
hardening a strip of blade steel; forming a cutting edge on the
hardened strip; after forming the cutting edge, bending the strip
along its length by coining the strip; and separating the bent
strip into individual blades, each blade having a bent portion.
[0015] Some embodiments may include one or more of the following
features. The strip may be bent using a forming die that is
configured so as not to touch the cutting edge. Bending the strip
may reduce the thickness of the blade steel in the bent portion by
at least about five percent relative to an original thickness of
the blade steel.
[0016] The invention also features razors and razor cartridges
including the cutting members described herein.
[0017] Embodiments can include one or more of the following
advantages.
[0018] In some embodiments, the cutting member can be affixed to a
cartridge of the shaving razor without the use of bent supports.
Consequently, the shaving razor can include fewer components and,
therefore, can be more cost-efficient than many conventional
shaving razors.
[0019] In certain embodiments, the cutting member has a thickness
that provides sufficient rigidity to prevent substantial
deformation of the cutting member during use of the shaving
razor.
[0020] In some embodiments, the cutting member is formed of a blade
steel that has a hardness sufficient for forming a cutting edge
that can cut hair, and has a ductility that is sufficient to allow
bending of the blade without fracture or other substantial
defects.
[0021] In some embodiments, the cutting members can be formed using
a substantially continuous manufacturing process.
[0022] Other features and advantages of the invention can be found
in the description, the drawings, and the claims.
DESCRIPTION OF DRAWINGS
[0023] FIG. 1 is a cross-sectional view of a prior art razor blade
assembly including a planar cutting member attached to a bent
support.
[0024] FIG. 2A is a cross-sectional view of an embodiment of a bent
cutting member for a shaving razor.
[0025] FIG. 2B is a top view of the cutting member of FIG. 2A.
[0026] FIG. 2C is a front view of the cutting member of FIG.
2A.
[0027] FIG. 3 illustrates a shaving razor that includes the bent
cutting member of FIG. 2A.
[0028] FIG. 4 illustrates a method and apparatus for forming the
cutting member of FIG. 2A.
[0029] FIG. 5 is a partial top view of a strip of blade steel after
exiting a cutting device of the apparatus shown in FIG. 4.
[0030] FIG. 6 is a partial top view of the strip of blade steel
after exiting a bending device of the apparatus shown in FIG.
4.
[0031] FIG. 7 is a cross-sectional view of the strip of blade steel
taken along line 7-7 in FIG. 4.
[0032] FIGS. 8A and 8B illustrate an embodiment of a method of
forming a bent region in the strip of blade steel.
DETAILED DESCRIPTION
[0033] Referring to FIG. 2A, a cutting member 100 includes a blade
portion 105, a base portion 110, and a bent portion 115 that
interconnects blade and base portions 105, 110. Blade portion 105
terminates in a relatively sharp cutting edge 120, while base
portion 110 terminates in a relatively blunt end region.
[0034] As shown in FIG. 3, cutting member 100 can be used in
shaving razor 210, which includes a handle 212 and a replaceable
shaving cartridge 214. Cartridge 214 includes housing 216, which
carries three cutting members 100, a guard 220, and a cap 222. In
other embodiments, the cartridge may include fewer or more
blades.
[0035] Cutting members 100 can be mounted within cartridge 214
without the use of additional supports (e.g., without the use of
bent metal supports like the one shown in FIG. 1). Cutting members
100 are captured at their ends and by a spring support under the
blade portion 105. The cutting members are allowed to move, during
shaving, in a direction generally perpendicular to the length of
blade portion 105. As shown in FIGS. 2A and 2B, the lower base
portions 110 of cutting members 100 extend to the sides beyond the
upper bent and blade portions 115, 105. The lower base portions 110
can be arranged to slide up and down within slots in cartridge
housing 216 while the upper portion rests against resilient arms
during shaving. The slots of the cartridge housing 216 have back
stop portions and front stop portions that define, between them, a
region in which cutting members 100 can move forward and backward
as they slide up and down in the slots during shaving. The front
stop portions are generally positioned beyond the ends of blade
portions 105, so as not to interfere with movement of blade
portions 105. Cutting members 100 are arranged within cartridge 214
such that cutting edges 220 are exposed. Cartridge 214 also
includes an interconnect member 224 on which housing 216 is
pivotally mounted at two arms 228. When cartridge 214 is attached
to handle 212 (e.g., by connecting interconnect member 224 to
handle 212), as shown in FIG. 3, a user can move the relatively
flat face of cartridge 214 across his/her skin in a manner that
permits cutting edges 120 of cutting members 100 to cut hairs
extending from the user's skin.
[0036] Referring again to FIG. 2, blade portion 105 of cutting
member 100 has a length of about 0.032 inch (0.82 millimeters) to
about 0.059 inch (1.49 millimeters). Base portion 110 has a length
of about 0.087 inch (2.22 millimeters) to about 0.093 inch (2.36
millimeters). Bent portion 115 has a bend radius R of about 0.020
inch (0.45 millimeter) or less (e.g., about 0.012 inch (0.30
millimeter)). Relative to base portion 110, blade portion 105
extends at an angle of about 115 degrees or less (e.g., about 108
degrees to about 115 degrees, about 110 to about 113 degrees).
Cutting edge 120 of blade portion 105 has a wedge-shaped
configuration with an ultimate tip having a radius less than about
1000 angstroms (e.g., from about 200 to about 300 angstroms).
[0037] In certain embodiments, cutting member 100 is relatively
thick, as compared to many conventional razor blades. Cutting
member 100, for example, can have an average thickness of at least
about 0.003 inch (0.076 millimeter), e.g., about 0.005 inch (0.127
millimeter) to about 0.01 inch (0.254 millimeter). As a result of
its relatively thick structure, cutting member 100 can provide
increased rigidity, which can improve the comfort of the user
and/or the cutting performance of cutting member 100 during use. In
some embodiments, cutting member 100 has a substantially constant
thickness. For example, blade portion 105 (except for cutting edge
120), base portion 110, and bent portion 115 can have substantially
the same thickness.
[0038] In some embodiments, the thickness of bent portion 115 is
less than the thickness of blade portion 105 and/or base portion
110. For example, the thickness of bent portion 115 can be less
than the thickness of blade portion 105 and/or base portion 110 by
at least about five percent (e.g., about five percent to about 30
percent, about ten percent to about 20 percent).
[0039] In certain embodiments, cutting member 100 (e.g., base
portion 110 of cutting member 100) has a hardness of about 540 HV
to about 750 HV (e.g., about 540 HV to about 620 HV). Bent portion
115 can, for example, have a hardness of about 540 HV to about 620
HV. The hardness of cutting member 100 can be measured by ASTM
E92-82--Standard Test Method for Vickers Hardness of Metallic
Materials.
[0040] In some embodiments, cutting member 100 (e.g., bent portion
115 of cutting member 100) has a ductility of about seven percent
to about 12 percent (e.g., about nine percent to about ten percent)
elongation measured in uniaxial tension at fracture. The ductility
of bent portion 115 can be measured, for example, by ASTM
E345-93--Standard Test Methods of Tension Testing of Metallic
Foil.
[0041] In some embodiments, bent portion 115 and the remainder of
cutting member 100 have substantially the same ductility.
[0042] Cutting member 100 can be formed of any of various suitable
materials. In certain embodiments, cutting member 100 is formed of
a material having a composition comprised of about 0.35 to about
0.43 percent carbon, about 0.90 to about 1.35 percent molybdenum,
about 0.40 to about 0.90 percent manganese, about 13 to about 14
percent chromium, no more than about 0.030 percent phosphorus,
about 0.20 to about 0.55 percent silicon, and no more than about
0.025 percent sulfur. Cutting member 100 can, for example, be
formed of a stainless steel having a carbon content of about 0.4
percent by weight, a chromium content of about 13 percent by
weight, a molybdenum content of about 1.25 percent by weight, and
amounts of manganese, chromium, phosphorus, silicon and sulfur
within the above ranges..
[0043] In some embodiments, blade portion 105 and/or base portion
110 have minimal levels of bow and sweep. Bow is a term used to
describe an arching normal to the plane in which the portion of the
cutting member is intended to lie. Sweep, also commonly referred to
as camber, is a term used to describe an arching within the plane
in which the portion of the cutting member lies (e.g., an arching
of the longitudinal edges of the portion of the cutting member). In
some embodiments, blade portion 105 has a bow of about +0.0004 to
about -0.002 inch (+0.01 to -0.05 millimeter) or less across the
length of the blade portion. In certain embodiments, blade portion
105 has a sweep of about .+-.0.0027 inch (.+-.0.07 millimeter) or
less across the length of the blade portion. Base portion 110 can
have a bow of about .+-.0.0024 inch (.+-.0.060 millimeter) or less
across the length of the base portion. By reducing the levels of
bow and/or sweep in blade portion 105 and/or base portion 110, the
comfort of the user and/or the cutting performance of cutting
member 100 can be improved.
[0044] FIG. 4 shows a method and apparatus 300 for forming cutting
members 100. A continuous strip of blade steel 350 is conveyed
(e.g., pulled by a rotating roll from a roll 305 of blade steel to
a heat-treating device 310, where strip 350 is heat-treated to
increase the hardness of the blade steel. Strip 350 is then
re-coiled into a roll 305 of hardened blade steel, and subsequently
unwound and conveyed to a sharpening device 315, where the hardened
edge region of the strip is sharpened to form a cutting edge 352.
Strip 350 is again re-coiled into a roll 305 of hardened and
sharpened blade steel, after which it is coated with hard and
lubricious coatings using a coating device 325. Strip 350 is then
unwound and conveyed to a cutting/stamping station which includes a
cutting device 320. Cutting device 320 creates transverse slots 355
and adjoining slits 357 (FIG. 5) across longitudinally spaced apart
regions of strip 350 (as shown in FIG. 5). Strip 350 is then
conveyed to a bending device 330, within the cutting/stamping
station, that creates a longitudinal bend 360 in the regions of
strip 350 between transverse slots 355 (shown in FIGS. 6 and 7).
After being bent, strip 350 is separated into multiple, discrete
cutting members 100 by a separating device 335, also within the
cutting/stamping station. Cutting members 100 may then be arranged
in a stack 340 for transport and/or for further processing, or
assembled directly into cartridges, and a scrap region 365 of strip
350 is assembled onto roll 345 for recycling or disposal. Scrap
region 365, for example, can be used merely to help convey strip
350 through the blade forming devices described above.
Alternatively or additionally, any of various other techniques can
be used to convey strip 350 through the blade forming devices.
[0045] Sharpening device 315 can be any device capable of
sharpening the edge of strip 350. Examples of razor blade cutting
edge structures and processes of manufacture are described in U.S.
Pat. Nos. 5,295,305; 5,232,568; 4,933,058; 5,032,243; 5,497,550;
5,940,975; 5,669,144; EP 0591334; and PCT 92/03330, which are
hereby incorporated by reference.
[0046] Cutting device 320 can be any of various devices capable of
providing slots 355 and/or slits 357 in strip 350. In some
embodiments, cutting device is a punch press. In such embodiments,
the progression of strip 350 can be periodically paused in order to
allow the punch press to stamp slots 355 and/or slits 357 in strip
350. Cutting device 320 can alternatively or additionally be any of
various other devices, such as a high power laser or a scoring
operation followed by a bending or fracturing operation.
[0047] Referring again to FIG. 5, after strip 350 has been conveyed
through cutting device 320, strip 350 includes multiple,
longitudinally spaced apart slots 355 and that extend inwardly from
the sharpened edge of the strip to a central region of the strip.
Slits 357 extend inwardly from slots 355. Slots 355 are spaced
apart by a distance that corresponds to the width of cutting
members 100. In some embodiments, adjacent slots 355 are spaced
apart from one another by about 36.20 millimeters to about 36.50
millimeters. In certain embodiments, adjacent slits are spaced
apart from one another by about 37.26 millimeters to about 37.36
millimeters. By providing discrete regions that are separated by
slots 355, the bending of strip 350 can be improved.
[0048] Bending device 330 can be any device capable of forming a
longitudinal bend in strip 350. In some embodiments, as shown in
FIGS. 8A and 8B, bending device 330 is an assembly that includes a
punch 365 and a die 370. Punch 365 includes a curved portion 367
that is configured to mate with an associated curved portion 372 of
die 370. Generally, curved portion 367 of punch 365 has a radius
that is slightly larger than a radius of curved portion 372 of die
370. Curved portion 367 of punch 365, for example can have a radius
of about 0.0231'' to about 0.0241'', while curved portion 372 of
die 370 can have a radius of about 0.010'' to about 0.014''. Punch
365 also includes a protrusion 369 that is configured to contact a
portion of strip 350 that, as discussed below, is offset from
sharpened edge 352 of strip 350.
[0049] To form bent region 360 of strip 350, the relatively planar
strip 350 is positioned between punch 365 and die 370, as shown in
FIG. 8A. Punch 365 and die 370 are then moved toward one another
such that curved portions 367 and 372 generally mate. Punch 365
can, for example, be moved toward die 370 at a rate of about 25
ft/min (10 m/min) to about 500 ft/min (200 m/min). As punch 365 and
die 370 are moved toward one another, protrusion 369 of punch 365
contacts a region of strip 350 offset from sharpened edge 352. As
punch 365 and die 370 mate with one another, strip 350 is deformed
into a bent position between punch 365 and die 370. Due to the
configuration of punch 365 and die 367, sharpened edge 352 can
remain untouched throughout the bending process. This to
arrangement can help to prevent damage to the relatively delicate,
sharpened edge 352 of strip 350.
[0050] As a result of the bending process, the thickness of strip
350 in bent region 360 can be reduced, relative to the thickness of
strip 350 prior to being bent, by at least about five percent
(e.g., about five percent to about 30 percent). Strip 350 in bent
region 360, for example, can have a thickness of about 0.0035 inch
(0.089 millimeter) to about 0.0095 inch (0.241 millimeter), while
the remainder of strip 350 can have a thickness of about 0.005 inch
(0.127 millimeter) to about 0.01 inch (0.254 millimeter).
[0051] Separating device 335 can be any device capable of
separating the regions of strip 350 between slots 355 from the
remainder of strip 350 to form discrete cutting members 100. In
some embodiments, separating device 335 is a punch press. The
progression of strip 350 can be periodically paused to allow the
punch press to accurately separate the regions of strip 350 between
slots 355 from the remainder of strip 350 to form cutting members
100.
[0052] Other devices capable of separating the regions of strip 350
between slots 355 from the remainder of strip 350 can alternatively
or additionally be used. Examples of such devices include a high
power laser or a scoring operation followed by a bending or
fracturing operation.
[0053] While certain embodiments have been described, other
embodiments are possible.
[0054] As an example, the order of many of the process steps
discussed above can be altered. The process steps can be ordered in
any of various different combinations.
[0055] Other embodiments are within the scope of the claims.
* * * * *